The present invention relates to a document filing system which stores electrical signals representing picture information such as documents and, when desired, retrieves desired picture information to display and/or print the same.
A filing system for recording the document information on a microfilm in a size-reduction manner has been known as a system for storing an enormous amount of the document information produced in companies and offices in a space-saving and retrieval manner. The microfilm filing system has succeeded in saving the space for keeping the document information, but has not succeeded in quickly and effectively retrieving and sampling desired information from a mass of the information.
An electronic document information filing system has been developed, superseding the microfilm filing system. The filing system two-dimensionally scans the document to be retained by laser beams, forms electrical image signals representing the scanned document contents by means of a photo multiplier, and records the image signals into a recording medium in a high recording density. In this type of filing system the filing information, corresponding to all the picture information, called "file structure" are stored. The file structure includes index information representing locations on a recording medium where the picture information are stored and further retrieval codes generally representing the picture information. When a desired retrieval code is keyed in from an input section including a keyboard, the document picture information corresponding to the file structure containing the retrieval code are retrieved and extracted, and finally are displayed on a display device. If the extracted document contents are to be printed, a corresponding key is depressed to print out the extracted document contents in hard copy form.
According to the filing system, the file structure are comprised of retrieval codes prepared by the operator and index information indicating storage addresses for document picture information. When information desired is to be extracted from the document picture information, filed in the filing system, an operator must designate a retrieval code corresponding to the desired picture information by operating the keyboard. The retrieval code is usually formed of characters and/or numerals of a number of digits. Therefore, when the retrieval code is formed of characters and/or numerals of 20 digits, the operator must operate keys on the keyboard at least 20 times for designating one piece of the picture information. The key operations are troublesome and time-consuming for the operator, adding to the work load of the operator.